Contact structures on open 3-manifolds

In this paper, we study contact structures on any open 3-manifold V which is the interior of a compact 3-manifold. To do this, we introduce proper contact isotopy invariants called the slope at infinity and the division number at infinity. We first prove several classification theorems for T^2 x [0, \infty), T^2 x R, and S^1 x R^2 using these concepts. This investigation yields infinitely many tight contact structures on T^2 x [0,\infty), T^2 x R, and S^1 x R^2 which admit no precompact embedding into another tight contact structure on the same space. Finally, we show that if V is irreducible and has an end of nonzero genus, then there are uncountably many tight contact structures on V that are not contactomorphic, yet are isotopic. Similarly, there are uncountably many overtwisted contact structures on V that are not contactomorphic, yet are isotopic.Comment: 18 pages, 3 figures, additions to intro, clearer statement of thm 1.1 (same proof), Modifications made to section 6 giving shorter proof of thm 1.2 and 1.

Land Grant Application- Tripp, James (Tauton)

Land grant application submitted to the Maine Land Office for James Tripp for service in the Revolutionary War.https://digitalmaine.com/revolutionary_war_mass/1358/thumbnail.jp

Choosing Poorly: Reward-Induced Strategy Shifts in Estimating the Probabilitiesof Conjunctions and Disjunctions

Human estimates of the probabilities of combinations of events show well-established violations of probabilitytheory, most notably the conjunction and disjunction fallacies. These violations have led researchers to conclude that therules of probability are too complex for most people to use, and that cognitively-easier approximations such as averagingare used instead. Unlike previous work that has assumed that individuals use only a single combination rule, we collectedrepeated estimates of conjunctions and disjunctions and investigated whether individuals consistently used a single rule orused a repertoire of rules in a trial-by-trial Bayesian analysis. When not incentivized, most participants were best describedas randomly selecting a combination rule on each trial, and the correct rule was the most often used. Despite this, whenincentivized to use their single-best strategy participants were more likely to use the incorrect averaging rule. People do notseem to understand their own strategies well

Nitrogen deposition and the sustainability of lowland heathlands in Britain

Despite widespread conservation efforts, global heathland area has substantially decreased in recent decades. Heathland habitats require low nitrogen availability in order to persist. Over the past 150 years, however, nitrogen deposition has increased markedly. Early observational studies and research using artificial N applications have identified N deposition as the primary driver of heathland succession into grassland or woodland, and N enrichment is considered a threat to heathland sustainability. This study investigated soil fertility and vegetation composition at 25 lowland heathland sites in low rainfall regions of mainland Britain within a modelled wet N deposition range of 1.85 to 10.90 kg N ha-1 y-1. A bioassay approach was used to quantify relationships between soil fertility and N deposition, heathland patch size and the management regimes. This study discovered significant positive relationships between N enrichment and C. vulgaris shoot mass, N and P concentrations. No relationship between N enrichment and N : P mass ratio was found suggesting no N induced shift to P limitation. It was determined that soil phosphomonoesterase activity was not up-regulated in response to N enrichment. This suggests that the soil P reserves are sufficient to satisfy demand under current N deposition loads. Heathland patch size was negatively related to C .vulgaris shoot dry-mass which was used as a proxy for soil fertility. Measured atmospheric ammonia concentrations were not related to C. vulgaris growth and shoot chemistry. No relationships were found between any variable tested and heathland vegetation composition suggesting that local factors, such as management intervention, may be substantial determinants of vegetation composition. This study presents relationships between temperature at origin and C. vulgaris growth from populations located along a latitudinal gradient in Western Europe. The findings of this thesis have implications for current heathland management, and for future management under a climate change scenario

Declining Recruitment and Growth of Shovelnose Sturgeon in the Middle Mississippi River: Implications for Conservation

To determine how populations of shovelnose sturgeon Scaphirhynchus platorynchus are changing and may respond to poor environmental conditions, current commercial harvest of black-egg (sexually mature) females, and incidental mortality of males, we require annual information about sex-specific age structure as it relates to the recruitment of new cohorts. We sampled shovelnose sturgeon by use of gill nets (5-cm bar mesh) monthly during 2002-2006 in the Middle Mississippi River between Cairo, Illinois, and St. Louis, Missouri. We compared patterns of size and age structure over time and projected age structure and population size into the future. Sex ratio in 2005-2006 was 1.14:1.00 (416 males and 363 females; P = 0.06), deviating from the 1:1 ratio that occurred in 2002-2003. Annual mortality increased from 37% in 2002-2003 to 44% by 2005-2006. Female shovelnose sturgeon were larger than males. Across years, the population shifted toward longer, older fish, and growth in length declined. Recruitment declined through time (29% per year). If these trends continue and if immigration from nonharvested populations is limited, population density may decline by an order of magnitude within one decade. Under current conditions, resilience to harvest and environmental perturbations is probably limited

Investing in Mobility: Freight Transport in the Hudson Region

Proposes a framework for assessing alternative investments in freight rail, highway, and transit capacity that would increase the ability to improve mobility and air quality in the New York metropolitan area